Phonograph cartridge with very hard metal ceramic frame

Abstract

A pick up cartridge which comprises a cantilever at the end of which is mounted, a stylus a generating mechanism which is fixed near the supporting point of the cantilever, a pair of yokes which give a magnetic field to the generating mechanism, and a holder which holds the yokes directly and/or indirectly, wherein at least a part of said holder is made of very hard metal ceramic material. Viscoelastic material is also used to reduce harmful vibrations in the cartridge.

I claim: 
     
       1. In a pick up cartridge comprising: a frame member (11); an elongated cantilever member (17); a stylus (18) mounted to an end of said elongated cantilever member (17); a pair of yokes (15, 16) mounted in said frame member (11) with a space formed between said yokes; a generating mechanism (19) electrically coupled to said cantilever (17); and said cantilever (17) being supported between said yokes and said generating mechanism being fixed near a supporting point of said cantilever, said pair of yokes providing a magnetic field to said mechanism; the improvement wherein at least a part of said frame member (11) is made of very hard ceramic material.   
     
     
       2. The pick up cartridge of claim 1 wherein said cantilever (17) is supported substantially at the center of the space formed between said pair of yokes. 
     
     
       3. The pick up cartridge of claim 1, further comprising a casing for said generating mechanism and said yokes; and viscoelastic material (25, 26) located between at least one of said yokes (15, 16) and said casing for absorbing vibrations. 
     
     
       4. The pick up cartridge of claim 3 wherein said viscoelastic material is silicone rubber grease which becomes solid at room temperature. 
     
     
       5. The pick up cartridge of any one of claims 1, 2, 3 or 4 wherein said cantilever (17) extends to at least one of said yokes and is supported thereby at a supporting point by said at least one yoke. 
     
     
       6. The pick up cartridge of one of claims 1 or 2 comprising a casing for said generating mechanism and said yokes, at least a part of said casing comprising said frame member (11). 
     
     
       7. The pick up cartridge of any one of claims 1, 2, 3 or 4 wherein said yokes (15, 16) are directly mounted to said frame member (11). 
     
     
       8. The pick up cartridge of any one of claims 1 or 2 wherein said yokes (15, 16) are mounted to said frame member (11) at their fulcrum; and further comprising a mass of viscoelastic material holding at least one of said yokes in position relative to said frame member. 
     
     
       9. The pick up cartridge of claim 8 wherein said cantilever (17) extends to at least one of said yokes and is supported thereby at a supporting point by said at least one yoke. 
     
     
       10. The pick up cartridge of claim 8 comprising a casing for said generating mechanism and said yokes, at least a part of said casing comprising said frame member (11). 
     
     
       11. The pick up cartridge of claim 8 wherein said viscoelastic material is silicone rubber grease which becomes solid at room temperature.